Pressure Drop Measurement of Liquid-Nitrogen Flow in Conductor Conduit of Cables

The cooling-span length design of the high-Tc superconducting cable system applied with liquid-nitrogen flow must be investigated to determine whether its use is practical. The liquid-nitrogen flow system design involves many difficulties due to its low friction factor. To investigate the pressure drop of liquid-nitrogen flow in the conductor conduits of real-scale cables, not only the straight conduit but also the corrugated conduit are providing a straight portion of 25 m. Comparison of the experimental results for each conduit pressure drop shows that the friction factor of the corrugated conduit is larger than the design value if the Reynolds number is kept constant. Thus, the result, should be applied in the design of a high-Tc super-conducting system.